The present invention relates to a structure of speaker which includes a metallic disk body connected to a sound coil with its center. The disk body radiates heat produced from vibration of speakers effectively so as to obtained increased working hours and better sound quality.
The quality of a sound system can be ascertained by listening to the sound effect of a host unit, amplifier and speaker. A speaker plays a key role in a sound system for it is the sound transmitter of the entire sound system and the sound source directly contacted by the user's ears. Therefore, a pair of quality speakers can be much more expensive than the price of other sound systems and that's why the speaker is so valuable and important.
A speaker converts electric oscillation into voice/sound waves for transmitting voice/sound to the user's ears. Referring to FIG. 1, the speaker 1 comprises a sound coil 11 winding with coil 10 where the sound coil is mounted in a magnetic seat 12. When electric power is connected to the coil 10, the coil 10 will produce magnetism to form a repulsive effect with the seat 12 to cause the sound coil 11 to move laterally on the intermediate shaft 120 of the seat 12 and such movement will drive the belly plate 13 in connection with the sound coil. This source of a vibration wave causes a change of a sound wave in the air when the belly plate 13 is reciprocally driven by the sound coil 11, and that is why we can hear the voice/sound transmitted from the speaker.
Referring to FIG. 1, we may know the action of speaker is achieved through reciprocal movement of sound coil 11 driving the belly plate 13, and therefore the sound coil 11 will continue to move in the intermediate shaft 120 of the seat 12. There has been little difference of inside/outside diameter between the sound coil 11 and intermediate shaft 120, i.e. the inside diameter of sound coil 11 is little greater than the outside diameter of the intermediate shaft 120. With such a condition, it is impossible for impurities to appear between the inside diameter of sound coil and the outside diameter of the intermediate shaft of the seat. To prevent the intrusion of dust from the sound coil, the conventional speaker has a cone to cover the joint between the sound coil 11 and belly plate 13, which is also known as a dust cover 14 sticking to the surface of belly plate 13 for covering the opening of the sound coil so as to prevent dust from intruding.
The conventional art of using dust cover to prevent the speaker from intrusion by impurity is not a bad idea but actually it provides some obstacle to the performance of a speaker and even to the technical breakthrough of speaker. The defects lie in the following:
1. The dust cover is made from compacted paper and its cover position is located on the belly plate without direct communication with sound coil; therefore high temperature caused by reciprocal movement of sound coil can not be radiated. PA1 2. High temperature caused by improper location of the dust cover relative to the sound coil will result in the surrounding coil of sound coil burning down and therefore, shorten life span of the speaker. PA1 3. Because the sound coil can not effectively radiate heat unsmooth movement will result in distortion of the sound wave released by the speaker to deteriorate performance and sound quality. PA1 4. When the dust cover sticks to the belly plate without direct connection with the sound coil, the speaker can not deliver heat from the sound coil and this will also reduce the resistance of speaker to vibration. Therefore, the conventional speaker should require another independent speaker because one single speaker can not fully demonstrate tweeter and woofer sound qualities for there is a great difference of sound wave vibration between a tweeter and a woofer. PA1 5. The defect arising from a tweeter and a woofer which cannot be fully demonstrated by one single speaker will result in increasing the consumer's budget and more trouble with the performance of the tweeter where reduced quality lies in improper location and material of dust cover.
The aforesaid defects relating to the conventional speaker have caused severe trouble to users; the speaker is often found burning down or breaking down due to vibration in poolhalls, dancing pubs and areas having singing performances because continuous play is required for a long time. Some sound system users also feel troubled because of failing to enjoy higher quality of sound.